There has been some kind of fortification on the hill overlooking Ljubljana since at least the time of the Celts and Illyrians. The Romans had a military post here. The beginnings of the present day castle go back to the 9th century with a wooden fortress, although the castle building is first mentioned only in 1144. Th existing building mostly dates from the 16th century following the earthquake of 1511 with further renovations in the 17th century when it started being used as a royal residence. The castle was then turned into a prison in the beginning of the 19th century and was used as such right up until 1945. After this the castle deteriorated until it was restored fairly recently.

Inside, you can visit the virtual museum which is a 3D video presentation charting the history of the castle and the growth and building of the city. It goes on for about 30mins and is well worth a visit. Also included in the price is a visit to the Viewing Tower where the views over the city and surrounding area are pretty spectacular.